These chromatograms show how easy it is to increase your column loading to maximize detector and to obtain purified compounds for off-line MS-MS, FTIR or NMR Analysis.

Follow this paradigm from a Cogent™ "Half" Column that has the best selectivity and efficiency with the best method you can develop and you will be able to predict which column to use to prepare and/or detect trace impurities in the shortest amount of time possible.

   

Mini-Scout Column	50mm x 4.6mm 0.01mg load 1ml/min 5µl Inj				50mm x 4.6mm 0.01mg load 4ml/min 5µl Inj
	50mm x 7.8mm 0.01mg load 10ml/min 5µl Inj				50mm x 7.8mm 0.01mg load 1ml/min 5µl Inj
	50mm x 21.2mm 0.1mg load 5ml/min 50µl Inj		50mm x 21.2mm 0.1mg load 15ml/min 50µl Inj		50mm x 21.2mm 75.0mg load 5ml/min 500µl Inj		50mm x 21.2mm 75.0mg load 15ml/min 500µl Inj

It is very well known that resolution can be increased by increasing column length but at the cost of increasing back pressure and limiting your ability to increase flow and decrease time. This can be a problem when you want to load more sample on your column for trace amount analysis.

In this RR we show that you can get the same or better resolution by keeping the column length constant and increasing column ID. You can increase the flow rate keeping time of analysis acceptable due to less back pressures limits as shown in the first three chromatograms.

The final three chromatograms show that for a 21.2mm ID column, increasing length from 50mm to 100 mm and finally to 250mm lengths, allows you additional resolution and or loading.

The Van Deemter predicts rapid de-optimization below the optimal flow rate, the drop in de-optimazation is much less severe above its optimal flow rate.